Anabolic effect of prostaglandin E2 on cortical bone of aged male rats comes mainly from modeling-dependent bone gain

In this study, prostaglandin E₂ (3 mg/kg per day) was administered to 20-month-old male Wistar rats for 10 and 30 days. Histomorphometric analyses were performed on double-fluorescent-labeled undecalcified tibial shaft sections. Thirty days of prostaglandin E₂ (PGE₂) administration increased bone formation rate/total bone surface from undetectable levels to 0.6 μm/day at the periosteal surface and from 0.5 to 2.1 μm/day at the endocortical surface. Endocortical osteoid surface area increased from 2% to 67% at day 10 and decreased to 6% at day 30; woven and lamellar bone formation started at day 0, but was most obvious at day 30, resulting in a 12% increase of total bone mass. The red to yellow marrow ratio was 0.2 in pretreatment controls, and increased to 1.6 by day 10 and 2.4 by day 30 with PGE₂ administration. Intracortical cavity number and area increased after 10 days of PGE₂ treatment, but with forming osteon number and area far exceeding those of resorption cavities at day 30. Endocortical modeling surface/endocortical surface was only 1.5%, and remodeling was 11.1% in pretreatment controls. PGE₂ treatment increased modeling to 24.5% in the 10 day group and 93.7% in the 30 day group, whereas remodeling remained unchanged at 10 days, and decreased to 6.2% at 30 days. Osteoprogenitor cells and osteoblasts could not be detected in pretreatment controls, but increased by day 10, and returned almost to control levels by 30 days. Our data indicate that PGE₂ induced periosteal and endocortical bone formation mainly by modeling-dependent bone gain, accompanied by increases in intracortical remodeling and red bone marrow, and a transient increase in the osteoprogenitor cells adjacent to the endocortical surface. These findings suggest that 20-month-old male Wistar rats were very responsive to the anabolic action of PGE₂ in the tibial shaft, a site consisting mainly of cortical bone and yellow marrow.     

The matrix comes to lung transplantation

Lung transplantation is complicated by fibroproliferation, which is likely mediated in part by matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs. This commentary briefly discusses what is known about these mediators in fibrotic pulmonary diseases and how an important new study by Yoshida and colleagues sheds light on the diverse functions of these proteins in alloimmune inflammation.     

Anabolic effect of prostaglandin E2 on cortical bone of aged male rats comes mainly from modeling-dependent bone gain

In this study, prostaglandin E₂ (3 mg/kg per day) was administered to 20-month-old male Wistar rats for 10 and 30 days. Histomorphometric analyses were performed on double-fluorescent-labeled undecalcified tibial shaft sections. Thirty days of prostaglandin E₂ (PGE₂) administration increased bone formation rate/total bone surface from undetectable levels to 0.6 μm/day at the periosteal surface and from 0.5 to 2.1 μm/day at the endocortical surface. Endocortical osteoid surface area increased from 2% to 67% at day 10 and decreased to 6% at day 30; woven and lamellar bone formation started at day 0, but was most obvious at day 30, resulting in a 12% increase of total bone mass. The red to yellow marrow ratio was 0.2 in pretreatment controls, and increased to 1.6 by day 10 and 2.4 by day 30 with PGE₂ administration. Intracortical cavity number and area increased after 10 days of PGE₂ treatment, but with forming osteon number and area far exceeding those of resorption cavities at day 30. Endocortical modeling surface/endocortical surface was only 1.5%, and remodeling was 11.1% in pretreatment controls. PGE₂ treatment increased modeling to 24.5% in the 10 day group and 93.7% in the 30 day group, whereas remodeling remained unchanged at 10 days, and decreased to 6.2% at 30 days. Osteoprogenitor cells and osteoblasts could not be detected in pretreatment controls, but increased by day 10, and returned almost to control levels by 30 days. Our data indicate that PGE₂ induced periosteal and endocortical bone formation mainly by modeling-dependent bone gain, accompanied by increases in intracortical remodeling and red bone marrow, and a transient increase in the osteoprogenitor cells adjacent to the endocortical surface. These findings suggest that 20-month-old male Wistar rats were very responsive to the anabolic action of PGE₂ in the tibial shaft, a site consisting mainly of cortical bone and yellow marrow.     

梅花香自苦寒来

中国医科大学附属第一医院烧伤科创建于1958年.半个世纪以来,烧伤科医护人员先后在韩凤玉、王誉先、薛宝升、孙树等几代烧伤专家的领导下,开拓进取、忘我工作、精益求精,使烧伤科不断发展,治疗水平不断提高.至今已成功救治各类烧伤、瘢痕及复杂难治性创面患者1万余例,治愈率为96.15%,达国内先进水平.科室现为国家、省、市三级突发事件指定应急救治单位,是本地区技术力量雄厚、设施齐全的烧伤抢救治疗中心.     

抛光对牙齿表面色素再沉着的影响

目的：观察超声洁治及喷砂法去除色素后，牙齿表面抛光对牙外源性色素再沉着的影响。方法：用红茶和洗必泰液作为外源性着色液，以超声洁治和喷砂法去除32颗牙齿色素后，随机分为抛光组和对照组并浸入外源性着色液，记录实验前后牙齿表面白色度值，比较抛光对牙齿表面着色的影响。结果：经抛光处理后，牙齿表面的外源性色素附着明显减少，抛光组的白色度值明显低于对照组。结论：抛光牙齿表面，可以明显减少外源性色素的再附着。     

Hemoptysis is frequently fatal if blood comes directly from the aorta commentary

Physicians throughout the world, across various specialties, are faced with diagnostic challenges of appropriately identifying the source of hemotosysis, which could range from a simple treatable infection, to the more ominous massive hemorrhage from the aorta requiring emergency, life saving surgery. Aortobronchopulmonary fistula, which is an abnormal communication between the thoracic aorta and the pulmonary tree, is an uncommon but often lethal condition if not promptly surgically intervened. Over the decades, the underlying cause has shifted, from primarily due to an aortic infection, such as tuberculosis, to now secondarily as a result of endovascular repair of the intrathoracic aorta. The best treatment modality, whether open surgical repair, endovascular management, or hybrid approach continues to be debated given the high operative morbidity and mortality of open repair and need to address the pulmonary communication, with optimal management still undetermined.     

Dialysis adequacy reconsidered: The person comes first

Although many nephrologists see value in maximizing clearance and time on dialysis, clinical trials have failed to show a clear and consistent benefit of increasing clearance above the minimum threshold level recommended in clinical practice guidelines or of increasing dialysis session length or frequency. Available evidence suggests that patients and clinicians do not necessarily agree on what matters most when it comes to dialysis care, and that what patients consider to be an adequate dialysis session is highly individual and has little to do with solute clearance. Qualitative studies suggest that patients value spending less time on dialysis, having the dialysis procedure go smoothly, and being treated like an individual by staff members. Because many patients feel that they have little choice but to show up for their dialysis sessions, failing to involve them in decisions about time spent on the machine can contribute to feelings of powerlessness and loss of control, erode their sense of self, and diminish the quality of therapeutic relationships. On the other hand, a flexible and shared approach to decision-making about time spent on dialysis (and other aspects of care) can help to strengthen relationships, uphold personhood, and align care with what matters most.